The invention relates in general to wells and in particular to initiating flow from a well.
To initiate the flow of oil and/or other materials in a well, a conventional shaped charge warhead (or perforator) is fired through the well casing, the cement sheath and into the earthen formation. A shaped charge device comprises a shaped charge liner backed by high explosives. When the explosives are detonated, the shaped charge device forms a high velocity forward moving penetrator or “jet” that is capable of deeply penetrating the targeted material.
Output of a well is dependent on several factors including the size of the hole made by the perforator, the hole shape and the penetration depth. Fracturing fluids are pumped into the hole to fracture the rock formation and special agents in the fluid hold the fractures open to allow flow. Small diameter holes (as produced by conventional shaped charges) have a tendency to clog with these agents. Currently available perforators are designed to produce deep penetration but with a very small diameter hole.
One method of increasing hole size uses multiple initiation points to alter the perforator jet output. This method requires significantly changing the current perforator manufacturing procedures, the perforator external hardware and the way the perforators are integrated into the holding apparatus. Other methods to alter jet output are being investigated. U.S. Pat. No. 6,925,924 issued on Aug. 9, 2005 includes a detailed description of the well perforation process and is incorporated by reference herein.